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80 SMT007 MAGAZINE I SEPTEMBER 2018 A team of researchers at Harvard's Wyss Institute for Biologically Inspired Engineering, Harvard John A. Paul- son School of Engineering and Applied Sciences (SEAS), and Boston University now has overcome the challenge of creating multifunctional flexible robots that can move and operate at smaller size scales by developing an integrated fabrication process that enables the design of soft robots on the millimeter scale with micrometer-scale features. To demonstrate the capabilities of their new technology, they created a robotic soft spider from a single elastic material with body-shaping, motion, and color features. In their Microfluidic Origami for Reconfigurable Pneu- matic/Hydraulic (MORPH) devices, the team first used a soft lithography technique to generate 12 layers of an elastic silicone that together constitute the soft spider's material basis. Each layer is precisely cut out of a mold with a laser-micromachining technique, and then bonded to the one below to create the rough 3D structure of the soft spider. Next, a pre-conceived network of hollow microflu- idic channels was integrated into individual layers. With a third technique known as injection induced self-fold- ing, they pressurized one set of these integrated micro- fluidic channels with a curable resin from the outside. This induces individual layers, and with them also their neigh- boring layers, to locally bend into their final configura- tion, which is fixed in space when the resin hardens. This way, for example, the soft spider's swollen abdomen and downward-curved legs become permanent features. "By developing a new hybrid technology that merges three different fabrication techniques, we created a soft robotic spider made only of sili - cone rubber with 18 degrees of freedom, encom- passing changes in structure, motion, and color, and with tiny features in the micrometer range," said Sheila Russo, Ph.D., co-author of the study. She helped initiate the project as a Postdoctoral Fellow in Robert Wood's group at the Wyss Insti - tute and SEAS and now is Assistant Professor at Boston University. The study is published in Advanced Materials. (Source: Wyss Institute at Harvard University) Researchers Develop Small, Multifunctional Robots ronment and will invariably need to be tested and verified ahead of the production run. How has the trend for miniaturisation affected the development of coatings? The trend towards miniaturisation is most evident in consumer electronics and has led to the development of ultra-thin coating mate- rials with thicknesses of less than 12 microns. This, in combination with internal gasketing and better case design, has enabled the pro- duction of vastly more water-resistant mobile phones and other handheld devices. In more traditional applications, such as aerospace and automotive, there is a dou- ble issue of finer pitch components (reduced space between conductors) and a need to reduce weight, resulting in less protection being afforded by the board's housing. The impact of this is that coatings need to function more as a primary mitigation strategy against the environment. As a result, the performance requirements of these coating materials have increased dramatically, especially with regards to condensation resistance. SMT007 Phil Kinner is the global business/ technical director for conformal coatings at Electrolube. To read past columns or contact Kinner, click here. To download your copy of Electrolube's micro eBook written by Kinner, The Printed Circuit Assembler's Guide to… Conformal Coatings for Harsh Environments, click here.